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EP-4470898-B1 - MOTOR AND ELECTRIC BICYCLE

EP4470898B1EP 4470898 B1EP4470898 B1EP 4470898B1EP-4470898-B1

Inventors

  • TAKAHASHI, RYOSUKE
  • OYAMA, SEIICHI

Dates

Publication Date
20260513
Application Date
20240529

Claims (12)

  1. A motor (10) for assisting driving of an electric bicycle (20), said motor comprising: a rotor (100) having a rotor shaft (160) extending along a virtual central axis, the rotor (100) rotating about the rotor shaft (160); a stator (200) positioned radially outside with respect to the rotor (100) and including a stator core (210), an insulator (220) covering the stator core (210), a coil (230) wound around the insulator (220), and a covering portion (240) covering the coil (230); a hub (300) that accommodates the rotor (100) and the stator (200) and rotates with rotation of the rotor (100); a torque sensor (500) positioned on an axial one side with respect to the rotor (100); a circuit board (400) accommodated in the hub (300) and positioned between the rotor (100) and the torque sensor (500), wherein the circuit board (400) is disposed radially inside relative to the coil (230) and faces the coil (230) in the radial direction; a sensor wire (550) electrically connecting the torque sensor (500) and the circuit board (400); a signal wire (450) electrically connected to an external circuit on a surface on an axial one side of the circuit board (400); and a first fixed shaft (610) that is a stationary member and is positioned on an axial one side with respect to the rotor shaft (160), wherein the first fixed shaft (610) supports the torque sensor (500).
  2. The motor (10) according to claim 1 further comprising: a first stator cover (260) covering an axial one side of the stator (200); and a second stator cover (270) covering an axial other side of the stator (200), wherein the circuit board (400) is positioned between the rotor (100) and the first stator cover (260), and the first stator cover (260) is provided with a through hole through which the sensor wire (550) and the signal wire (450) penetrate in an axial direction.
  3. The motor (10) according to claim 2, wherein at least a part of the first fixed shaft (610) extends from the hub (300) to an axial one side, the first fixed shaft (610) is attached with the torque sensor (500), and the first fixed shaft (610) includes a tube portion in which the signal wire (450) is internally disposed.
  4. The motor (10) according to claim 3, wherein the first fixed shaft (610) further includes a base portion (614) coupled to the tube portion, the base portion (614) is attached to the first stator cover (260), and the base portion (614) is provided with a cutout continuous with a through hole of the tube portion.
  5. The motor (10) according to claim 3 or 4 further comprising: a second fixed shaft (620) that is a stationary member and is positioned on an axial other side with respect to the rotor shaft (160), wherein at least a part of the second fixed shaft (620) extends from the hub (300) to an axial other side.
  6. The motor (10) according to any one of claims 1 to 5 further comprising: a control wire for supplying the stator (200) with a control current, wherein the first fixed shaft (610) includes a tube portion in which the control wire is internally disposed.
  7. The motor (10) according to any one of claims 1 to 6 further comprising: a sun gear (710) attached to an axial other side with respect to the rotor shaft (160); and a planetary gear (720) that meshes with the sun gear (710) and is disposed on an axial other side with respect to the rotor (100).
  8. The motor (10) according to any one of claims 1 to 7 further comprising a one-way clutch attached to the rotor shaft (160).
  9. The motor (10) according to any one of claims 1 to 8, wherein the sensor wire (550) includes: a sensor connection line connected to the torque sensor (500), a first connector positioned at a tip end of the sensor connection line, a board connection line connected to the circuit board (400), and a second connector positioned at a tip end of the board connection line and connected to the first connector.
  10. An electric bicycle comprising: the motor (10) according to any one of claims 1 to 9; a front wheel; and a rear wheel that rotates with rotation of the motor (10).
  11. The electric bicycle according to claim 10, wherein the hub (300) of the motor (10) is the hub (300) of the rear wheel.
  12. An electric bicycle comprising: the motor (10) according to any one of claims 1 to 9; a front wheel; a rear wheel that rotates with rotation of the motor (10); and a sprocket attached to the rear wheel, wherein the sprocket faces the first fixed shaft (610).

Description

Technical Field The present invention relates to a motor and an electric bicycle. Background Art In recent years, pedelecs have been rapidly spreading. The pedelec can reduce the driver's pedaling force by using the power of an electric motor as auxiliary power (see, for example, Patent Literature 1). Patent Literature 1 describes a freehub torque speed sensing device that can accumulate a torque sensor in a freehub of an electric bicycle or a bicycle. In the freehub torque speed sensing device of Patent Literature 1, a freehub body is provided with a torque sensing deformation unit, whereby the completed vehicle can be more conveniently assembled. Citation List Patent Literature Patent Literature 1: JP 2022-517380 A CN 207 766 108 U discloses a motor hub structure including a hub motor, a flywheel seat disposed on the main shaft of the hub motor, and a flywheel disposed on the flywheel base. In particular, said CN 207 766 108 U discloses a motor for assisting driving of an electric bicycle, said motor comprising: a rotor having a rotor shaft extending along a virtual central axis, the rotor rotating about the rotor shaft;a stator positioned radially outside with respect to the rotor;a hub that accommodates the rotor and the stator and rotates with rotation of the rotor;a torque sensor positioned on an axial one side with respect to the rotor;a circuit board accommodated in the hub and positioned between the rotor and the torque sensor;a sensor wire electrically connecting the torque sensor and the circuit board;a signal wire electrically connected to an external circuit on a surface on an axial one side of the circuit board; anda first fixed shaft that is a stationary member and is positioned on an axial one side with respect to the rotor shaft, wherein the first fixed shaft supports the torque sensor. Summary of Invention Technical Problem In the freehub torque speed sensing device described in Patent Literature 1, a lead wire extends from an axis opposite to a torque sensor and a sprocket. For this reason, the lead wire extending from the torque sensor to the outside may become long. The present invention has been made in view of the above problems, and an object of the present invention is to provide a motor and an electric bicycle that can simplify routing of a lead wire. Solution to Problem According to the present invention, a motor defined in claim 1 is provided. Exemplary embodiments are defined in the dependent claims. An exemplary electric bicycle according to the present invention includes: the motor described above; a front wheel; and a rear wheel that rotates with rotation of the motor. Another exemplary electric bicycle according to the present invention includes: the motor described above; a front wheel; a rear wheel that rotates with rotation of the motor; and a sprocket attached to the rear wheel, wherein the sprocket faces the first fixed shaft. Advantageous Effects of Invention According to the exemplary present invention, it is possible to provide a motor in which a torque sensor is integrated with a rotor and a stator. Brief Description of Drawings Fig. 1 is a cross-sectional view illustrating a structure of a motor according to an embodiment of the present invention.Fig. 2 is a perspective view of the motor according to the embodiment of the present invention.Fig. 3 is an exploded perspective view of the motor according to the embodiment of the present invention.Fig. 4A is a partially enlarged view of Fig. 3.Fig. 4B is a partially enlarged view of Fig. 3.Fig. 5 is a perspective view of a rotor in the motor according to the embodiment of the present invention.Fig. 6 is an exploded perspective view of a torque sensor, a first fixed shaft, the rotor, the stator, a first stator cover, a body portion, and a circuit board in the motor according to the embodiment of the present invention.Fig. 7 is an exploded perspective view of the torque sensor, the first fixed shaft, the rotor, the stator, the first stator cover, the body portion, and the circuit board in the motor according to the embodiment of the present invention.Fig. 8 is a schematic perspective view of the stator in the motor according to the embodiment of the present invention.Fig. 9 is a schematic view of an electric bicycle including the motor according to the embodiment of the present invention.Fig. 10 is a schematic perspective view illustrating a part of the electric bicycle including the motor according to the embodiment of the present invention. Description of Embodiments Hereinafter, an exemplary embodiment of the present invention will be described with reference to the drawings. In the drawings, the identical or corresponding parts will be denoted by the identical reference signs and description of such parts will not be repeated. In the present description, for convenience, there is a case where the direction of a rotation axis AX (see Fig. 1) of the motor is described as a horizontal direction. In the drawings, an X axi